The moving contact line problem is a classical problem in fluid mechanics. 
The difficulty stems from the fact that the classical Navier-Stokes equation with the no-slip 
boundary condition predicts a non-physical singularity at the contact line with infinite 
rate of energy dissipation. In this talk, we will discuss how the continuum theory, 
molecular dynamics and the more recently developed multiscale techniques can be 
combined to give us a better understanding of the fundamental physics of 
the moving contact line and formulate simple and effective models. 
We also illustrate how this model can be used to analyze the behavior of the 
apparent contact angle, hysteresis and other important physical problems for the moving contact line.